How silly is it that I didn't think of blending options as a way to blend layers together with other layers?
I know I know, but I usually find that if a person learns Photoshop in a certain mechanical way then they typically make a special place in their brain for that exact mechanical application. In my case, I learned blending options for text and text only for design application. It was a good day when I finally realized I could use it for pixel layers and/or parts of an image. Compositing instantly got so much easier!
The blending options provide what I think is the single best thing that I found for increasing the believability in a LOT of composites. That single best thing is: INNER GLOW
A lot of people composite their subject layers, whether they be people or objects, over a background layer that is brighter than the subject layer itself. If the background is something like a sky or any sort of reflective light source then it looks unnatural to have something in front of it without the light influencing that layer.
When compositing a darker layer over top of it lighter layer, typically the lighter layer would be seen as a light source or a source that has a lot light bouncing off of it. In real life to some degree there is a light wrap that would bounce off of the light source and wrap around the darker object in front of it. The goal is to recreate this effect in Photoshop as easily as possible.
What typically gives the composite layer away is the fact that the edges of the darker object on top tend to look a bit too hard and crisp. If you have a mask on that object then your inclination might be to feather that mask and soften the edges. Instead what I suggest is keep the edges as they are and gradate the edges from dark to light by using an INNER GLOW.
Once you put the inner glow onto the layer all you have to do is sample the colour from the colour that's directly on the outside of the edge of the subject layer. That will take the color of the pixels that's right beside it and gradate it inward into the edge of the composited layer. My suggestion to make it look as though it's closer to a real light wrap is to increase the size of the glow considerably and lower the opacity to make it much more subtle.
Applying an inner glow doesn’t only lighten the shadows around the edges, it also pours the surrounding colour into that area creating a much more color correct feel for the item in its environment.
I typically suggest applying the blending mode effects before your individual color correction for that layer.